I just assembled my Ancheer folding ebike. There is a red button on the right side of the handlebar, just below the light switch. What is that?

Could be the main on/off button that starts up the bike electronics. Could also be a horn button. Is it the folding frame with 26" wheels or one of the little folders with 16" and 20" wheels?

Hope you figured it out and are enjoying the ride!

It's the horn. I found out by touching it by accident, which is both easy and common.

Are you kidding? I figured at the very least the horn did not work.

Everything's still working just fine. I put 12.8 miles on the bike today, per Google Maps. "You get what you pay for" is mostly marketing.